1. Field of the Invention
The present invention relates to an apparatus for producing trichlorosilane. Priority is claimed on Japanese Patent Application No. 2011-259483, filed Nov. 28, 2011, the content of which is incorporated herein by reference.
2. Description of Related Art
Trichlorosilane (SiHCl3) used as raw material for producing high-purity silicon (Si) can be produced from silicon tetrachloride (SiCl4) and hydrogen.
Silicon is produced by reductive reaction and thermal decomposition reaction of trichlorosilane according to below reaction formulas (1) and (2). Trichlorosilane used for these reactions is produced by reaction according to below reaction formula (3).SiHCl3+H2→Si+3HCl  (1)4SiHCl3→Si+3SiCl4+2H2  (2)SiCl4+H2→SiHCl3+HCl  (3)
Reaction of the formula (3) is caused by introducing raw gas including silicon tetrachloride and hydrogen into a high-temperature reaction vessel. For example, in Japanese Patent No. 3,781,439, an apparatus for producing trichlorosilane having a structure in which heating elements surround a double-pipe reaction chamber having an outer chamber and an inner chamber formed by two concentric pipes is proposed.
That is to say, in the apparatus for producing trichlorosilane mentioned in Japanese Patent No. 3,781,439, the raw gas preheated in a heat exchanger provided under the reaction chamber is introduced from below to, the outer chamber of the reaction chamber, flows upward in the outer chamber while being heated, turns at an upper part of the outer chamber so as to be introduced into the inner chamber, flows downward in the inner chamber, and then is discharged from a lower part of the inner chamber.